Field of the Invention
The present invention relates most generally to environmental control systems for use in controlled environment agriculture (“CEA”) facilities, and more particularly to atmospheric gas control systems for CEA facilities, and still more particularly to a CO2 generator and controller for monitoring, generating, and thereby enriching CO2 gas concentrations in the atmosphere surrounding agricultural crops, and/or horticultural and pharmaceutical plants in a CEA facility.
Background Discussion
It is well-established that plant and crop yields can be increased by enhancing CO2 concentrations in the atmosphere immediately surrounding the growing plants. When the many variables affecting plant metabolism and growth are closely controlled—such as light, nutrients, temperature, humidity, soil and water pH, and the like—there are measurable benefits to be realized by providing and controlling increased atmospheric CO2 concentrations. The accepted optimal concentration is now understood to be approximately 1500 ppm for plants generally, while normal atmospheric concentrations at sea level average around 300 ppm. Greater concentrations than 1,500 ppm can be toxic to the plants, and lower concentrations results in slower growth rates. Accordingly, it is desirable to keep atmospheric CO2 at optimal elevated levels in CEA facilities.
However, not all controlled environment agriculture (“CEA”) facilities are the same. Grow room size, air circulation patterns, light heating and cooling systems, the integrity of seals on greenhouse panels, doors, and windows, and so forth, can all have considerable effects on CO2 gas containment and escape. Accordingly, a system to maintain CO2 at optimal levels must both monitor ambient concentrations and must generate gas in precise amounts.
Unfortunately, known systems operate in binary fashion only—on or off—and do not provide CO2 generation in amounts carefully tailored to changing grow room conditions. At a minimum, such systems waste energy, and therefore money, but they also fail to create the optimal growing conditions for plants, which is also wasteful and uneconomical, inasmuch as growing times are extended, delaying product readiness for markets, and resources needed for plant growth are consumed over longer periods of time. Indeed, this is the perennial problem for CEA operators: how to produce high quality marketable crops and plants using resources in the most economical way. It is well understood that achieving those ends requires careful resource control strategies and techniques that manage plant growth resources (water, air, light and dark, nutrients, temperature, humidity, etc., and CO2), while balancing the provision of optimal resources with practical costs. The present invention addresses this need.